var block = {
  newline: /^\n+/,
  code: /^( {4}[^\n]+\n*)+/,
  fences: /^ {0,3}(`{3,}|~{3,})([^`~\n]*)\n(?:|([\s\S]*?)\n)(?: {0,3}\1[~`]* *(?:\n+|$)|$)/,
  hr: /^ {0,3}((?:- *){3,}|(?:_ *){3,}|(?:\* *){3,})(?:\n+|$)/,
  heading: /^ {0,3}(#{1,6}) +([^\n]*?)(?: +#+)? *(?:\n+|$)/,
  blockquote: /^( {0,3}> ?(paragraph|[^\n]*)(?:\n|$))+/,
  list: /^( {0,3})(bull) [\s\S]+?(?:hr|def|\n{2,}(?! )(?!\1bull )\n*|\s*$)/,
  html: '^ {0,3}(?:' + // optional indentation
        '<(script|pre|style)[\\s>][\\s\\S]*?(?:</\\1>[^\\n]*\\n+|$)' + // (1)
        '|comment[^\\n]*(\\n+|$)' + // (2)
        '|<\\?[\\s\\S]*?\\?>\\n*' + // (3)
        '|<![A-Z][\\s\\S]*?>\\n*' + // (4)
        '|<!\\[CDATA\\[[\\s\\S]*?\\]\\]>\\n*' + // (5)
        '|</?(tag)(?: +|\\n|/?>)[\\s\\S]*?(?:\\n{2,}|$)' + // (6)
        '|<(?!script|pre|style)([a-z][\\w-]*)(?:attribute)*? */?>(?=[ \\t]*(?:\\n|$))[\\s\\S]*?(?:\\n{2,}|$)' + // (7) open tag
        '|</(?!script|pre|style)[a-z][\\w-]*\\s*>(?=[ \\t]*(?:\\n|$))[\\s\\S]*?(?:\\n{2,}|$)' + // (7) closing tag
        ')',
  def: /^ {0,3}\[(label)\]: *\n? *<?([^\s>]+)>?(?:(?: +\n? *| *\n *)(title))? *(?:\n+|$)/,
  nptable: noop,
  table: noop,
  lheading: /^([^\n]+)\n {0,3}(=+|-+) *(?:\n+|$)/,
  // regex template, placeholders will be replaced according to different paragraph
  // interruption rules of commonmark and the original src spec:
  _paragraph: /^([^\n]+(?:\n(?!hr|heading|lheading|blockquote|fences|list|html)[^\n]+)*)/,
  text: /^[^\n]+/
}

block._label = /(?!\s*\])(?:\\[\[\]]|[^\[\]])+/
block._title = /(?:"(?:\\"?|[^"\\])*"|'[^'\n]*(?:\n[^'\n]+)*\n?'|\([^()]*\))/
block.def = edit(block.def)
  .replace('label', block._label)
  .replace('title', block._title)
  .getRegex()

block.bullet = /(?:[*+-]|\d{1,9}\.)/
block.item = /^( *)(bull) ?[^\n]*(?:\n(?!\1bull ?)[^\n]*)*/
block.item = edit(block.item, 'gm')
  .replace(/bull/g, block.bullet)
  .getRegex()

block.list = edit(block.list)
  .replace(/bull/g, block.bullet)
  .replace('hr', '\\n+(?=\\1?(?:(?:- *){3,}|(?:_ *){3,}|(?:\\* *){3,})(?:\\n+|$))')
  .replace('def', '\\n+(?=' + block.def.source + ')')
  .getRegex()

block._tag = 'address|article|aside|base|basefont|blockquote|body|caption' +
    '|center|col|colgroup|dd|details|dialog|dir|div|dl|dt|fieldset|figcaption' +
    '|figure|footer|form|frame|frameset|h[1-6]|head|header|hr|html|iframe' +
    '|legend|li|link|main|menu|menuitem|meta|nav|noframes|ol|optgroup|option' +
    '|p|param|section|source|summary|table|tbody|td|tfoot|th|thead|title|tr' +
    '|track|ul'
block._comment = /<!--(?!-?>)[\s\S]*?-->/
block.html = edit(block.html, 'i')
  .replace('comment', block._comment)
  .replace('tag', block._tag)
  .replace('attribute', / +[a-zA-Z:_][\w.:-]*(?: *= *"[^"\n]*"| *= *'[^'\n]*'| *= *[^\s"'=<>`]+)?/)
  .getRegex()

block.paragraph = edit(block._paragraph)
  .replace('hr', block.hr)
  .replace('heading', ' {0,3}#{1,6} +')
  .replace('|lheading', '') // setex headings don't interrupt commonmark paragraphs
  .replace('blockquote', ' {0,3}>')
  .replace('fences', ' {0,3}(?:`{3,}|~{3,})[^`\\n]*\\n')
  .replace('list', ' {0,3}(?:[*+-]|1[.)]) ') // only lists starting from 1 can interrupt
  .replace('html', '</?(?:tag)(?: +|\\n|/?>)|<(?:script|pre|style|!--)')
  .replace('tag', block._tag) // pars can be interrupted by type (6) html blocks
  .getRegex()

block.blockquote = edit(block.blockquote)
  .replace('paragraph', block.paragraph)
  .getRegex()

/**
 * Normal Block Grammar
 */

block.normal = merge({}, block)

/**
 * GFM Block Grammar
 */

block.gfm = merge({}, block.normal, {
  nptable: /^ *([^|\n ].*\|.*)\n *([-:]+ *\|[-| :]*)(?:\n((?:.*[^>\n ].*(?:\n|$))*)\n*|$)/,
  table: /^ *\|(.+)\n *\|?( *[-:]+[-| :]*)(?:\n((?: *[^>\n ].*(?:\n|$))*)\n*|$)/
})

/**
 * Pedantic grammar (original John Gruber's loose src specification)
 */

block.pedantic = merge({}, block.normal, {
  html: edit(
    '^ *(?:comment *(?:\\n|\\s*$)' +
        '|<(tag)[\\s\\S]+?</\\1> *(?:\\n{2,}|\\s*$)' + // closed tag
        '|<tag(?:"[^"]*"|\'[^\']*\'|\\s[^\'"/>\\s]*)*?/?> *(?:\\n{2,}|\\s*$))')
    .replace('comment', block._comment)
    .replace(/tag/g, '(?!(?:' +
            'a|em|strong|small|s|cite|q|dfn|abbr|data|time|code|var|samp|kbd|sub' +
            '|sup|i|b|u|mark|ruby|rt|rp|bdi|bdo|span|br|wbr|ins|del|img)' +
            '\\b)\\w+(?!:|[^\\w\\s@]*@)\\b')
    .getRegex(),
  def: /^ *\[([^\]]+)\]: *<?([^\s>]+)>?(?: +(["(][^\n]+[")]))? *(?:\n+|$)/,
  heading: /^ *(#{1,6}) *([^\n]+?) *(?:#+ *)?(?:\n+|$)/,
  fences: noop, // fences not supported
  paragraph: edit(block.normal._paragraph)
    .replace('hr', block.hr)
    .replace('heading', ' *#{1,6} *[^\n]')
    .replace('lheading', block.lheading)
    .replace('blockquote', ' {0,3}>')
    .replace('|fences', '')
    .replace('|list', '')
    .replace('|html', '')
    .getRegex()
})

/**
 * Block Lexer
 */

function Lexer (options) {
  this.tokens = []
  this.tokens.links = Object.create(null)
  this.options = options || index.defaults
  this.rules = block.normal

  if (this.options.pedantic) {
    this.rules = block.pedantic
  } else if (this.options.gfm) {
    this.rules = block.gfm
  }
}

/**
 * Expose Block Rules
 */

Lexer.rules = block

/**
 * Static Lex Method
 */

Lexer.lex = function (src, options) {
  var lexer = new Lexer(options)
  return lexer.lex(src)
}

/**
 * Preprocessing
 */

Lexer.prototype.lex = function (src) {
  src = src
    .replace(/\r\n|\r/g, '\n')
    .replace(/\t/g, '    ')
    .replace(/\u00a0/g, ' ')
    .replace(/\u2424/g, '\n')

  return this.token(src, true)
}

/**
 * Lexing
 */

Lexer.prototype.token = function (src, top) {
  src = src.replace(/^ +$/gm, '')
  var next,
    loose,
    cap,
    bull,
    b,
    item,
    listStart,
    listItems,
    t,
    space,
    i,
    tag,
    l,
    isordered,
    istask,
    ischecked

  while (src) {
    // newline
    if (cap = this.rules.newline.exec(src)) {
      src = src.substring(cap[0].length)
      if (cap[0].length > 1) {
        this.tokens.push({
          type: 'space'
        })
      }
    }

    // code
    if (cap = this.rules.code.exec(src)) {
      var lastToken = this.tokens[this.tokens.length - 1]
      src = src.substring(cap[0].length)
      // An indented code block cannot interrupt a paragraph.
      if (lastToken && lastToken.type === 'paragraph') {
        lastToken.text += '\n' + cap[0].trimRight()
      } else {
        cap = cap[0].replace(/^ {4}/gm, '')
        this.tokens.push({
          type: 'code',
          codeBlockStyle: 'indented',
          text: !this.options.pedantic
            ? rtrim(cap, '\n')
            : cap
        })
      }
      continue
    }

    // fences
    if (cap = this.rules.fences.exec(src)) {
      src = src.substring(cap[0].length)
      this.tokens.push({
        type: 'code',
        lang: cap[2] ? cap[2].trim() : cap[2],
        text: cap[3] || ''
      })
      continue
    }

    // heading
    if (cap = this.rules.heading.exec(src)) {
      src = src.substring(cap[0].length)
      this.tokens.push({
        type: 'heading',
        depth: cap[1].length,
        text: cap[2]
      })
      continue
    }

    // table no leading pipe (gfm)
    if (cap = this.rules.nptable.exec(src)) {
      item = {
        type: 'table',
        header: splitCells(cap[1].replace(/^ *| *\| *$/g, '')),
        align: cap[2].replace(/^ *|\| *$/g, '').split(/ *\| */),
        cells: cap[3] ? cap[3].replace(/\n$/, '').split('\n') : []
      }

      if (item.header.length === item.align.length) {
        src = src.substring(cap[0].length)

        for (i = 0; i < item.align.length; i++) {
          if (/^ *-+: *$/.test(item.align[i])) {
            item.align[i] = 'right'
          } else if (/^ *:-+: *$/.test(item.align[i])) {
            item.align[i] = 'center'
          } else if (/^ *:-+ *$/.test(item.align[i])) {
            item.align[i] = 'left'
          } else {
            item.align[i] = null
          }
        }

        for (i = 0; i < item.cells.length; i++) {
          item.cells[i] = splitCells(item.cells[i], item.header.length)
        }

        this.tokens.push(item)

        continue
      }
    }

    // hr
    if (cap = this.rules.hr.exec(src)) {
      src = src.substring(cap[0].length)
      this.tokens.push({
        type: 'hr'
      })
      continue
    }

    // blockquote
    if (cap = this.rules.blockquote.exec(src)) {
      src = src.substring(cap[0].length)

      this.tokens.push({
        type: 'blockquote_start'
      })

      cap = cap[0].replace(/^ *> ?/gm, '')

      // Pass `top` to keep the current
      // "toplevel" state. This is exactly
      // how src.pl works.
      this.token(cap, top)

      this.tokens.push({
        type: 'blockquote_end'
      })

      continue
    }

    // list
    if (cap = this.rules.list.exec(src)) {
      src = src.substring(cap[0].length)
      bull = cap[2]
      isordered = bull.length > 1

      listStart = {
        type: 'list_start',
        ordered: isordered,
        start: isordered ? +bull : '',
        loose: false
      }
      this.tokens.push(listStart)

      // Get each top-level item.
      cap = cap[0].match(this.rules.item)

      listItems = []
      next = false
      l = cap.length
      i = 0

      for (; i < l; i++) {
        item = cap[i]

        // Remove the list item's bullet
        // so it is seen as the next token.
        space = item.length
        item = item.replace(/^ *([*+-]|\d+\.) */, '')

        // Outdent whatever the
        // list item contains. Hacky.
        if (~item.indexOf('\n ')) {
          space -= item.length
          item = !this.options.pedantic
            ? item.replace(new RegExp('^ {1,' + space + '}', 'gm'), '')
            : item.replace(/^ {1,4}/gm, '')
        }

        // Determine whether the next list item belongs here.
        // Backpedal if it does not belong in this list.
        if (i !== l - 1) {
          b = block.bullet.exec(cap[i + 1])[0]
          if (bull.length > 1 ? b.length === 1
            : (b.length > 1 || (this.options.smartLists && b !== bull))) {
            src = cap.slice(i + 1).join('\n') + src
            i = l - 1
          }
        }

        // Determine whether item is loose or not.
        // Use: /(^|\n)(?! )[^\n]+\n\n(?!\s*$)/
        // for discount behavior.
        loose = next || /\n\n(?!\s*$)/.test(item)
        if (i !== l - 1) {
          next = item.charAt(item.length - 1) === '\n'
          if (!loose) loose = next
        }

        if (loose) {
          listStart.loose = true
        }

        // Check for task list items
        istask = /^\[[ xX]\] /.test(item)
        ischecked = undefined
        if (istask) {
          ischecked = item[1] !== ' '
          item = item.replace(/^\[[ xX]\] +/, '')
        }

        t = {
          type: 'list_item_start',
          task: istask,
          checked: ischecked,
          loose: loose
        }

        listItems.push(t)
        this.tokens.push(t)

        // Recurse.
        this.token(item, false)

        this.tokens.push({
          type: 'list_item_end'
        })
      }

      if (listStart.loose) {
        l = listItems.length
        i = 0
        for (; i < l; i++) {
          listItems[i].loose = true
        }
      }

      this.tokens.push({
        type: 'list_end'
      })

      continue
    }

    // html
    if (cap = this.rules.html.exec(src)) {
      src = src.substring(cap[0].length)
      this.tokens.push({
        type: this.options.sanitize
          ? 'paragraph'
          : 'html',
        pre: !this.options.sanitizer &&
                    (cap[1] === 'pre' || cap[1] === 'script' || cap[1] === 'style'),
        text: this.options.sanitize ? (this.options.sanitizer ? this.options.sanitizer(cap[0]) : escape(cap[0])) : cap[0]
      })
      continue
    }

    // def
    if (top && (cap = this.rules.def.exec(src))) {
      src = src.substring(cap[0].length)
      if (cap[3]) cap[3] = cap[3].substring(1, cap[3].length - 1)
      tag = cap[1].toLowerCase().replace(/\s+/g, ' ')
      if (!this.tokens.links[tag]) {
        this.tokens.links[tag] = {
          href: cap[2],
          title: cap[3]
        }
      }
      continue
    }

    // table (gfm)
    if (cap = this.rules.table.exec(src)) {
      item = {
        type: 'table',
        header: splitCells(cap[1].replace(/^ *| *\| *$/g, '')),
        align: cap[2].replace(/^ *|\| *$/g, '').split(/ *\| */),
        cells: cap[3] ? cap[3].replace(/\n$/, '').split('\n') : []
      }

      if (item.header.length === item.align.length) {
        src = src.substring(cap[0].length)

        for (i = 0; i < item.align.length; i++) {
          if (/^ *-+: *$/.test(item.align[i])) {
            item.align[i] = 'right'
          } else if (/^ *:-+: *$/.test(item.align[i])) {
            item.align[i] = 'center'
          } else if (/^ *:-+ *$/.test(item.align[i])) {
            item.align[i] = 'left'
          } else {
            item.align[i] = null
          }
        }

        for (i = 0; i < item.cells.length; i++) {
          item.cells[i] = splitCells(
            item.cells[i].replace(/^ *\| *| *\| *$/g, ''),
            item.header.length)
        }

        this.tokens.push(item)

        continue
      }
    }

    // lheading
    if (cap = this.rules.lheading.exec(src)) {
      src = src.substring(cap[0].length)
      this.tokens.push({
        type: 'heading',
        depth: cap[2].charAt(0) === '=' ? 1 : 2,
        text: cap[1]
      })
      continue
    }

    // top-level paragraph
    if (top && (cap = this.rules.paragraph.exec(src))) {
      src = src.substring(cap[0].length)
      this.tokens.push({
        type: 'paragraph',
        text: cap[1].charAt(cap[1].length - 1) === '\n'
          ? cap[1].slice(0, -1)
          : cap[1]
      })
      continue
    }
    if (cap = this.rules.text.exec(src)) {
      src = src.substring(cap[0].length)
      this.tokens.push({
        type: 'text',
        text: cap[0]
      })
      continue
    }

    if (src) {
      throw new Error('Infinite loop on byte: ' + src.charCodeAt(0))
    }
  }
  return this.tokens
}

/**
 * Inline-Level Grammar
 */

var inline = {
  escape: /^\\([!"#$%&'()*+,\-./:;<=>?@\[\]\\^_`{|}~])/,
  autolink: /^<(scheme:[^\s\x00-\x1f<>]*|email)>/,
  url: noop,
  tag: '^comment' +
        '|^</[a-zA-Z][\\w:-]*\\s*>' + // self-closing tag
        '|^<[a-zA-Z][\\w-]*(?:attribute)*?\\s*/?>' + // open tag
        '|^<\\?[\\s\\S]*?\\?>' + // processing instruction, e.g. <?php ?>
        '|^<![a-zA-Z]+\\s[\\s\\S]*?>' + // declaration, e.g. <!DOCTYPE html>
        '|^<!\\[CDATA\\[[\\s\\S]*?\\]\\]>', // CDATA section
  link: /^!?\[(label)\]\(\s*(href)(?:\s+(title))?\s*\)/,
  reflink: /^!?\[(label)\]\[(?!\s*\])((?:\\[\[\]]?|[^\[\]\\])+)\]/,
  nolink: /^!?\[(?!\s*\])((?:\[[^\[\]]*\]|\\[\[\]]|[^\[\]])*)\](?:\[\])?/,
  strong: /^__([^\s_])__(?!_)|^\*\*([^\s*])\*\*(?!\*)|^__([^\s][\s\S]*?[^\s])__(?!_)|^\*\*([^\s][\s\S]*?[^\s])\*\*(?!\*)/,
  em: /^_([^\s_])_(?!_)|^\*([^\s*<\[])\*(?!\*)|^_([^\s<][\s\S]*?[^\s_])_(?!_|[^\spunctuation])|^_([^\s_<][\s\S]*?[^\s])_(?!_|[^\spunctuation])|^\*([^\s<"][\s\S]*?[^\s\*])\*(?!\*|[^\spunctuation])|^\*([^\s*"<\[][\s\S]*?[^\s])\*(?!\*)/,
  code: /^(`+)([^`]|[^`][\s\S]*?[^`])\1(?!`)/,
  br: /^( {2,}|\\)\n(?!\s*$)/,
  del: noop,
  text: /^(`+|[^`])(?:[\s\S]*?(?:(?=[\\<!\[`*]|\b_|$)|[^ ](?= {2,}\n))|(?= {2,}\n))/
}

// list of punctuation marks from common mark spec
// without ` and ] to workaround Rule 17 (inline code blocks/links)
inline._punctuation = '!"#$%&\'()*+,\\-./:;<=>?@\\[^_{|}~'
inline.em = edit(inline.em).replace(/punctuation/g, inline._punctuation).getRegex()

inline._escapes = /\\([!"#$%&'()*+,\-./:;<=>?@\[\]\\^_`{|}~])/g

inline._scheme = /[a-zA-Z][a-zA-Z0-9+.-]{1,31}/
inline._email = /[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+(@)[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)+(?![-_])/
inline.autolink = edit(inline.autolink)
  .replace('scheme', inline._scheme)
  .replace('email', inline._email)
  .getRegex()

inline._attribute = /\s+[a-zA-Z:_][\w.:-]*(?:\s*=\s*"[^"]*"|\s*=\s*'[^']*'|\s*=\s*[^\s"'=<>`]+)?/

inline.tag = edit(inline.tag)
  .replace('comment', block._comment)
  .replace('attribute', inline._attribute)
  .getRegex()

inline._label = /(?:\[[^\[\]]*\]|\\.|`[^`]*`|[^\[\]\\`])*?/
inline._href = /<(?:\\[<>]?|[^\s<>\\])*>|[^\s\x00-\x1f]*/
inline._title = /"(?:\\"?|[^"\\])*"|'(?:\\'?|[^'\\])*'|\((?:\\\)?|[^)\\])*\)/

inline.link = edit(inline.link)
  .replace('label', inline._label)
  .replace('href', inline._href)
  .replace('title', inline._title)
  .getRegex()

inline.reflink = edit(inline.reflink)
  .replace('label', inline._label)
  .getRegex()

/**
 * Normal Inline Grammar
 */

inline.normal = merge({}, inline)

/**
 * Pedantic Inline Grammar
 */

inline.pedantic = merge({}, inline.normal, {
  strong: /^__(?=\S)([\s\S]*?\S)__(?!_)|^\*\*(?=\S)([\s\S]*?\S)\*\*(?!\*)/,
  em: /^_(?=\S)([\s\S]*?\S)_(?!_)|^\*(?=\S)([\s\S]*?\S)\*(?!\*)/,
  link: edit(/^!?\[(label)\]\((.*?)\)/)
    .replace('label', inline._label)
    .getRegex(),
  reflink: edit(/^!?\[(label)\]\s*\[([^\]]*)\]/)
    .replace('label', inline._label)
    .getRegex()
})

/**
 * GFM Inline Grammar
 */

inline.gfm = merge({}, inline.normal, {
  escape: edit(inline.escape).replace('])', '~|])').getRegex(),
  _extended_email: /[A-Za-z0-9._+-]+(@)[a-zA-Z0-9-_]+(?:\.[a-zA-Z0-9-_]*[a-zA-Z0-9])+(?![-_])/,
  url: /^((?:ftp|https?):\/\/|www\.)(?:[a-zA-Z0-9\-]+\.?)+[^\s<]*|^email/,
  _backpedal: /(?:[^?!.,:;*_~()&]+|\([^)]*\)|&(?![a-zA-Z0-9]+;$)|[?!.,:;*_~)]+(?!$))+/,
  del: /^~+(?=\S)([\s\S]*?\S)~+/,
  text: /^(`+|[^`])(?:[\s\S]*?(?:(?=[\\<!\[`*~]|\b_|https?:\/\/|ftp:\/\/|www\.|$)|[^ ](?= {2,}\n)|[^a-zA-Z0-9.!#$%&'*+\/=?_`{\|}~-](?=[a-zA-Z0-9.!#$%&'*+\/=?_`{\|}~-]+@))|(?= {2,}\n|[a-zA-Z0-9.!#$%&'*+\/=?_`{\|}~-]+@))/
})

inline.gfm.url = edit(inline.gfm.url, 'i')
  .replace('email', inline.gfm._extended_email)
  .getRegex()
/**
 * GFM + Line Breaks Inline Grammar
 */

inline.breaks = merge({}, inline.gfm, {
  br: edit(inline.br).replace('{2,}', '*').getRegex(),
  text: edit(inline.gfm.text)
    .replace('\\b_', '\\b_| {2,}\\n')
    .replace(/\{2,\}/g, '*')
    .getRegex()
})

/**
 * Inline Lexer & Compiler
 */

function InlineLexer (links, options) {
  this.options = options || index.defaults
  this.links = links
  this.rules = inline.normal
  this.renderer = this.options.renderer || new Renderer()
  this.renderer.options = this.options

  if (!this.links) {
    throw new Error('Tokens array requires a `links` property.')
  }

  if (this.options.pedantic) {
    this.rules = inline.pedantic
  } else if (this.options.gfm) {
    if (this.options.breaks) {
      this.rules = inline.breaks
    } else {
      this.rules = inline.gfm
    }
  }
}

/**
 * Expose Inline Rules
 */

InlineLexer.rules = inline

/**
 * Static Lexing/Compiling Method
 */

InlineLexer.output = function (src, links, options) {
  var inline = new InlineLexer(links, options)
  return inline.output(src)
}

/**
 * Lexing/Compiling
 */

InlineLexer.prototype.output = function (src) {
  var out = ''
  var link
  var text
  var href
  var title
  var cap
  var prevCapZero

  while (src) {
    // escape
    if (cap = this.rules.escape.exec(src)) {
      src = src.substring(cap[0].length)
      out += escape(cap[1])
      continue
    }

    // tag
    if (cap = this.rules.tag.exec(src)) {
      if (!this.inLink && /^<a /i.test(cap[0])) {
        this.inLink = true
      } else if (this.inLink && /^<\/a>/i.test(cap[0])) {
        this.inLink = false
      }
      if (!this.inRawBlock && /^<(pre|code|kbd|script)(\s|>)/i.test(cap[0])) {
        this.inRawBlock = true
      } else if (this.inRawBlock && /^<\/(pre|code|kbd|script)(\s|>)/i.test(cap[0])) {
        this.inRawBlock = false
      }

      src = src.substring(cap[0].length)
      out += this.options.sanitize
        ? this.options.sanitizer
          ? this.options.sanitizer(cap[0])
          : escape(cap[0])
        : cap[0]
      continue
    }

    // link
    if (cap = this.rules.link.exec(src)) {
      var lastParenIndex = findClosingBracket(cap[2], '()')
      if (lastParenIndex > -1) {
        var linkLen = 4 + cap[1].length + lastParenIndex
        cap[2] = cap[2].substring(0, lastParenIndex)
        cap[0] = cap[0].substring(0, linkLen).trim()
        cap[3] = ''
      }
      src = src.substring(cap[0].length)
      this.inLink = true
      href = cap[2]
      if (this.options.pedantic) {
        link = /^([^'"]*[^\s])\s+(['"])(.*)\2/.exec(href)

        if (link) {
          href = link[1]
          title = link[3]
        } else {
          title = ''
        }
      } else {
        title = cap[3] ? cap[3].slice(1, -1) : ''
      }
      href = href.trim().replace(/^<([\s\S]*)>$/, '$1')
      out += this.outputLink(cap, {
        href: InlineLexer.escapes(href),
        title: InlineLexer.escapes(title)
      })
      this.inLink = false
      continue
    }

    // reflink, nolink
    if ((cap = this.rules.reflink.exec(src)) ||
            (cap = this.rules.nolink.exec(src))) {
      src = src.substring(cap[0].length)
      link = (cap[2] || cap[1]).replace(/\s+/g, ' ')
      link = this.links[link.toLowerCase()]
      if (!link || !link.href) {
        out += cap[0].charAt(0)
        src = cap[0].substring(1) + src
        continue
      }
      this.inLink = true
      out += this.outputLink(cap, link)
      this.inLink = false
      continue
    }

    // strong
    if (cap = this.rules.strong.exec(src)) {
      src = src.substring(cap[0].length)
      out += this.renderer.strong(this.output(cap[4] || cap[3] || cap[2] || cap[1]))
      continue
    }

    // em
    if (cap = this.rules.em.exec(src)) {
      src = src.substring(cap[0].length)
      out += this.renderer.em(this.output(cap[6] || cap[5] || cap[4] || cap[3] || cap[2] || cap[1]))
      continue
    }

    // code
    if (cap = this.rules.code.exec(src)) {
      src = src.substring(cap[0].length)
      out += this.renderer.codespan(escape(cap[2].trim(), true))
      continue
    }

    // br
    if (cap = this.rules.br.exec(src)) {
      src = src.substring(cap[0].length)
      out += this.renderer.br()
      continue
    }

    // del (gfm)
    if (cap = this.rules.del.exec(src)) {
      src = src.substring(cap[0].length)
      out += this.renderer.del(this.output(cap[1]))
      continue
    }

    // autolink
    if (cap = this.rules.autolink.exec(src)) {
      src = src.substring(cap[0].length)
      if (cap[2] === '@') {
        text = escape(this.mangle(cap[1]))
        href = 'mailto:' + text
      } else {
        text = escape(cap[1])
        href = text
      }
      out += this.renderer.link(href, null, text)
      continue
    }

    // url (gfm)
    if (!this.inLink && (cap = this.rules.url.exec(src))) {
      if (cap[2] === '@') {
        text = escape(cap[0])
        href = 'mailto:' + text
      } else {
        // do extended autolink path validation
        do {
          prevCapZero = cap[0]
          cap[0] = this.rules._backpedal.exec(cap[0])[0]
        } while (prevCapZero !== cap[0])
        text = escape(cap[0])
        if (cap[1] === 'www.') {
          href = 'http://' + text
        } else {
          href = text
        }
      }
      src = src.substring(cap[0].length)
      out += this.renderer.link(href, null, text)
      continue
    }

    // text
    if (cap = this.rules.text.exec(src)) {
      src = src.substring(cap[0].length)
      if (this.inRawBlock) {
        out += this.renderer.text(this.options.sanitize ? (this.options.sanitizer ? this.options.sanitizer(cap[0]) : escape(cap[0])) : cap[0])
      } else {
        out += this.renderer.text(escape(this.smartypants(cap[0])))
      }
      continue
    }

    if (src) {
      throw new Error('Infinite loop on byte: ' + src.charCodeAt(0))
    }
  }

  return out
}

InlineLexer.escapes = function (text) {
  return text ? text.replace(InlineLexer.rules._escapes, '$1') : text
}

/**
 * Compile Link
 */

InlineLexer.prototype.outputLink = function (cap, link) {
  var href = link.href
  var title = link.title ? escape(link.title) : null

  return cap[0].charAt(0) !== '!'
    ? this.renderer.link(href, title, this.output(cap[1]))
    : this.renderer.image(href, title, escape(cap[1]))
}

/**
 * Smartypants Transformations
 */

InlineLexer.prototype.smartypants = function (text) {
  if (!this.options.smartypants) return text
  return text
    // em-dashes
    .replace(/---/g, '\u2014')
  // en-dashes
    .replace(/--/g, '\u2013')
  // opening singles
    .replace(/(^|[-\u2014/(\[{"\s])'/g, '$1\u2018')
  // closing singles & apostrophes
    .replace(/'/g, '\u2019')
  // opening doubles
    .replace(/(^|[-\u2014/(\[{\u2018\s])"/g, '$1\u201c')
  // closing doubles
    .replace(/"/g, '\u201d')
  // ellipses
    .replace(/\.{3}/g, '\u2026')
}

/**
 * Mangle Links
 */

InlineLexer.prototype.mangle = function (text) {
  if (!this.options.mangle) return text
  var out = ''
  var l = text.length
  var i = 0
  var ch

  for (; i < l; i++) {
    ch = text.charCodeAt(i)
    if (Math.random() > 0.5) {
      ch = 'x' + ch.toString(16)
    }
    out += '&#' + ch + ';'
  }

  return out
}

/**
 * Renderer
 */

function Renderer (options) {
  this.options = options || index.defaults
}

Renderer.prototype.code = function (code, infostring, escaped) {
  var lang = (infostring || '').match(/\S*/)[0]
  if (this.options.highlight) {
    var out = this.options.highlight(code, lang)
    if (out != null && out !== code) {
      escaped = true
      code = out
    }
  }

  if (!lang) {
    return '<pre><code>' +
            (escaped ? code : escape(code, true)) +
            '</code></pre>'
  }

  return '<pre><code class="' +
        this.options.langPrefix +
        escape(lang, true) +
        '">' +
        (escaped ? code : escape(code, true)) +
        '</code></pre>\n'
}

Renderer.prototype.blockquote = function (quote) {
  return '<blockquote>\n' + quote + '</blockquote>\n'
}

Renderer.prototype.html = function (html) {
  return html
}

Renderer.prototype.heading = function (text, level, raw, slugger) {
  if (this.options.headerIds) {
    return '<h' +
            level +
            ' id="' +
            this.options.headerPrefix +
            slugger.slug(raw) +
            '">' +
            text +
            '</h' +
            level +
            '>\n'
  }
  // ignore IDs
  return '<h' + level + '>' + text + '</h' + level + '>\n'
}

Renderer.prototype.hr = function () {
  return this.options.xhtml ? '<hr/>\n' : '<hr>\n'
}

Renderer.prototype.list = function (body, ordered, start) {
  var type = ordered ? 'ol' : 'ul'
  var startatt = (ordered && start !== 1) ? (' start="' + start + '"') : ''
  return '<' + type + startatt + '>\n' + body + '</' + type + '>\n'
}

Renderer.prototype.listitem = function (text) {
  const reg = /\<input.+\>/
  let className = ''
  if (reg.test(text)) {
    className = 'list-item-checkbox'
    if (/checked/.test(text)) {
      className += ' list-item-checkbox-checked'
    }
  }
  return `<li class="${className} ">${text}</li>\n`
}

Renderer.prototype.checkbox = function (checked) {
  return '<input ' +
        (checked ? 'checked ' : '') +
        'disabled type="checkbox"' +
        (this.options.xhtml ? ' /' : '') +
        '> '
}

Renderer.prototype.paragraph = function (text) {
  return '<p>' + text + '</p>\n'
}

Renderer.prototype.table = function (header, body) {
  if (body) body = '<tbody>' + body + '</tbody>'

  return '<table>\n' +
        '<thead>\n' +
        header +
        '</thead>\n' +
        body +
        '</table>\n'
}

Renderer.prototype.tablerow = function (content) {
  return '<tr>\n' + content + '</tr>\n'
}

Renderer.prototype.tablecell = function (content, flags) {
  var type = flags.header ? 'th' : 'td'
  var tag = flags.align
    ? '<' + type + ' align="' + flags.align + '">'
    : '<' + type + '>'
  return tag + content + '</' + type + '>\n'
}

// span level renderer
Renderer.prototype.strong = function (text) {
  return '<strong>' + text + '</strong>'
}

Renderer.prototype.em = function (text) {
  return '<em>' + text + '</em>'
}

Renderer.prototype.codespan = function (text) {
  return '<code>' + text + '</code>'
}

Renderer.prototype.br = function () {
  return this.options.xhtml ? '<br/>' : '<br>'
}

Renderer.prototype.del = function (text) {
  return '<del>' + text + '</del>'
}

Renderer.prototype.link = function (href, title, text) {
  href = cleanUrl(this.options.sanitize, this.options.baseUrl, href)
  if (href === null) {
    return text
  }
  var out = '<a href="' + escape(href) + '"'
  if (title) {
    out += ' title="' + title + '"'
  }
  out += '>' + text + '</a>'
  return out
}

Renderer.prototype.image = function (href, title, text) {
  href = cleanUrl(this.options.sanitize, this.options.baseUrl, href)
  if (href === null) {
    return text
  }

  var out = '<img src="' + href + '" alt="' + text + '"'
  if (title) {
    out += ' title="' + title + '"'
  }
  out += this.options.xhtml ? '/>' : '>'
  return out
}

Renderer.prototype.text = function (text) {
  return text
}

/**
 * TextRenderer
 * returns only the textual part of the token
 */

function TextRenderer () {
}

// no need for block level renderers

TextRenderer.prototype.strong =
    TextRenderer.prototype.em =
        TextRenderer.prototype.codespan =
            TextRenderer.prototype.del =
                TextRenderer.prototype.text = function (text) {
                  return text
                }

TextRenderer.prototype.link =
    TextRenderer.prototype.image = function (href, title, text) {
      return '' + text
    }

TextRenderer.prototype.br = function () {
  return ''
}

/**
 * Parsing & Compiling
 */

function Parser (options) {
  this.tokens = []
  this.token = null
  this.options = options || index.defaults
  this.options.renderer = this.options.renderer || new Renderer()
  this.renderer = this.options.renderer
  this.renderer.options = this.options
  this.slugger = new Slugger()
}

/**
 * Static Parse Method
 */

Parser.parse = function (src, options) {
  var parser = new Parser(options)
  return parser.parse(src)
}

/**
 * Parse Loop
 */

Parser.prototype.parse = function (src) {
  this.inline = new InlineLexer(src.links, this.options)
  // use an InlineLexer with a TextRenderer to extract pure text
  this.inlineText = new InlineLexer(
    src.links,
    merge({}, this.options, { renderer: new TextRenderer() })
  )
  this.tokens = src.reverse()

  var out = ''
  while (this.next()) {
    out += this.tok()
  }

  return out
}

/**
 * Next Token
 */

Parser.prototype.next = function () {
  this.token = this.tokens.pop()
  return this.token
}

/**
 * Preview Next Token
 */

Parser.prototype.peek = function () {
  return this.tokens[this.tokens.length - 1] || 0
}

/**
 * Parse Text Tokens
 */

Parser.prototype.parseText = function () {
  var body = this.token.text

  while (this.peek().type === 'text') {
    body += '\n' + this.next().text
  }

  return this.inline.output(body)
}

/**
 * Parse Current Token
 */

Parser.prototype.tok = function () {
  switch (this.token.type) {
    case 'space': {
      return ''
    }
    case 'hr': {
      return this.renderer.hr()
    }
    case 'heading': {
      return this.renderer.heading(
        this.inline.output(this.token.text),
        this.token.depth,
        unescape(this.inlineText.output(this.token.text)),
        this.slugger)
    }
    case 'code': {
      return this.renderer.code(this.token.text,
        this.token.lang,
        this.token.escaped)
    }
    case 'table': {
      var header = ''
      var body = ''
      var i
      var row
      var cell
      var j

      // header
      cell = ''
      for (i = 0; i < this.token.header.length; i++) {
        cell += this.renderer.tablecell(
          this.inline.output(this.token.header[i]),
          { header: true, align: this.token.align[i] }
        )
      }
      header += this.renderer.tablerow(cell)

      for (i = 0; i < this.token.cells.length; i++) {
        row = this.token.cells[i]

        cell = ''
        for (j = 0; j < row.length; j++) {
          cell += this.renderer.tablecell(
            this.inline.output(row[j]),
            { header: false, align: this.token.align[j] }
          )
        }

        body += this.renderer.tablerow(cell)
      }
      return this.renderer.table(header, body)
    }
    case 'blockquote_start': {
      body = ''

      while (this.next().type !== 'blockquote_end') {
        body += this.tok()
      }

      return this.renderer.blockquote(body)
    }
    case 'list_start': {
      body = ''
      var ordered = this.token.ordered
      var start = this.token.start

      while (this.next().type !== 'list_end') {
        body += this.tok()
      }
      return this.renderer.list(body, ordered, start)
    }
    case 'list_item_start': {
      body = ''
      var loose = this.token.loose
      var checked = this.token.checked
      var task = this.token.task

      if (this.token.task) {
        body += this.renderer.checkbox(checked)
      }

      while (this.next().type !== 'list_item_end') {
        body += !loose && this.token.type === 'text'
          ? this.parseText()
          : this.tok()
      }
      return this.renderer.listitem(body, task, checked)
    }
    case 'html': {
      // TODO parse inline content if parameter src=1
      return this.renderer.html(this.token.text)
    }
    case 'paragraph': {
      return this.renderer.paragraph(this.inline.output(this.token.text))
    }
    case 'text': {
      return this.renderer.paragraph(this.parseText())
    }
    default: {
      var errMsg = 'Token with "' + this.token.type + '" type was not found.'
      if (this.options.silent) {
        console.log(errMsg)
      } else {
        throw new Error(errMsg)
      }
    }
  }
}

/**
 * Slugger generates header id
 */

function Slugger () {
  this.seen = {}
}

/**
 * Convert string to unique id
 */

Slugger.prototype.slug = function (value) {
  var slug = value
    .toLowerCase()
    .trim()
    .replace(/[\u2000-\u206F\u2E00-\u2E7F\\'!"#$%&()*+,./:;<=>?@[\]^`{|}~]/g, '')
    .replace(/\s/g, '-')

  if (this.seen.hasOwnProperty(slug)) {
    var originalSlug = slug
    do {
      this.seen[originalSlug]++
      slug = originalSlug + '-' + this.seen[originalSlug]
    } while (this.seen.hasOwnProperty(slug))
  }
  this.seen[slug] = 0

  return slug
}

/**
 * Helpers
 */

function escape (html, encode) {
  if (encode) {
    if (escape.escapeTest.test(html)) {
      return html.replace(escape.escapeReplace, function (ch) {
        return escape.replacements[ch]
      })
    }
  } else {
    if (escape.escapeTestNoEncode.test(html)) {
      return html.replace(escape.escapeReplaceNoEncode, function (ch) {
        return escape.replacements[ch]
      })
    }
  }

  return html
}

escape.escapeTest = /[&<>"']/
escape.escapeReplace = /[&<>"']/g
escape.replacements = {
  '&': '&amp;',
  '<': '&lt;',
  '>': '&gt;',
  '"': '&quot;',
  "'": '&#39;'
}

escape.escapeTestNoEncode = /[<>"']|&(?!#?\w+;)/
escape.escapeReplaceNoEncode = /[<>"']|&(?!#?\w+;)/g

function unescape (html) {
  // explicitly match decimal, hex, and named HTML entities
  return html.replace(/&(#(?:\d+)|(?:#x[0-9A-Fa-f]+)|(?:\w+));?/ig, function (_, n) {
    n = n.toLowerCase()
    if (n === 'colon') return ':'
    if (n.charAt(0) === '#') {
      return n.charAt(1) === 'x'
        ? String.fromCharCode(parseInt(n.substring(2), 16))
        : String.fromCharCode(+n.substring(1))
    }
    return ''
  })
}

function edit (regex, opt) {
  regex = regex.source || regex
  opt = opt || ''
  return {
    replace: function (name, val) {
      val = val.source || val
      val = val.replace(/(^|[^\[])\^/g, '$1')
      regex = regex.replace(name, val)
      return this
    },
    getRegex: function () {
      return new RegExp(regex, opt)
    }
  }
}

function cleanUrl (sanitize, base, href) {
  if (sanitize) {
    try {
      var prot = decodeURIComponent(unescape(href))
        .replace(/[^\w:]/g, '')
        .toLowerCase()
    } catch (e) {
      return null
    }
    if (prot.indexOf('javascript:') === 0 || prot.indexOf('vbscript:') === 0 || prot.indexOf('data:') === 0) {
      return null
    }
  }
  if (base && !originIndependentUrl.test(href)) {
    href = resolveUrl(base, href)
  }
  try {
    href = encodeURI(href).replace(/%25/g, '%')
  } catch (e) {
    return null
  }
  return href
}

function resolveUrl (base, href) {
  if (!baseUrls[' ' + base]) {
    // we can ignore everything in base after the last slash of its path component,
    // but we might need to add _that_
    // https://tools.ietf.org/html/rfc3986#section-3
    if (/^[^:]+:\/*[^/]*$/.test(base)) {
      baseUrls[' ' + base] = base + '/'
    } else {
      baseUrls[' ' + base] = rtrim(base, '/', true)
    }
  }
  base = baseUrls[' ' + base]

  if (href.slice(0, 2) === '//') {
    return base.replace(/:[\s\S]*/, ':') + href
  } else if (href.charAt(0) === '/') {
    return base.replace(/(:\/*[^/]*)[\s\S]*/, '$1') + href
  } else {
    return base + href
  }
}

var baseUrls = {}
var originIndependentUrl = /^$|^[a-z][a-z0-9+.-]*:|^[?#]/i

function noop () {
}

noop.exec = noop

function merge (obj) {
  var i = 1
  var target
  var key

  for (; i < arguments.length; i++) {
    target = arguments[i]
    for (key in target) {
      if (Object.prototype.hasOwnProperty.call(target, key)) {
        obj[key] = target[key]
      }
    }
  }

  return obj
}

function splitCells (tableRow, count) {
  // ensure that every cell-delimiting pipe has a space
  // before it to distinguish it from an escaped pipe
  var row = tableRow.replace(/\|/g, function (match, offset, str) {
    var escaped = false
    var curr = offset
    while (--curr >= 0 && str[curr] === '\\') escaped = !escaped
    if (escaped) {
      // odd number of slashes means | is escaped
      // so we leave it alone
      return '|'
    } else {
      // add space before unescaped |
      return ' |'
    }
  })
  var cells = row.split(/ \|/)
  var i = 0

  if (cells.length > count) {
    cells.splice(count)
  } else {
    while (cells.length < count) cells.push('')
  }

  for (; i < cells.length; i++) {
    // leading or trailing whitespace is ignored per the gfm spec
    cells[i] = cells[i].trim().replace(/\\\|/g, '|')
  }
  return cells
}

// Remove trailing 'c's. Equivalent to str.replace(/c*$/, '').
// /c*$/ is vulnerable to REDOS.
// invert: Remove suffix of non-c chars instead. Default falsey.
function rtrim (str, c, invert) {
  if (str.length === 0) {
    return ''
  }

  // Length of suffix matching the invert condition.
  var suffLen = 0

  // Step left until we fail to match the invert condition.
  while (suffLen < str.length) {
    var currChar = str.charAt(str.length - suffLen - 1)
    if (currChar === c && !invert) {
      suffLen++
    } else if (currChar !== c && invert) {
      suffLen++
    } else {
      break
    }
  }

  return str.substr(0, str.length - suffLen)
}

function findClosingBracket (str, b) {
  if (str.indexOf(b[1]) === -1) {
    return -1
  }
  var level = 0
  for (var i = 0; i < str.length; i++) {
    if (str[i] === '\\') {
      i++
    } else if (str[i] === b[0]) {
      level++
    } else if (str[i] === b[1]) {
      level--
      if (level < 0) {
        return i
      }
    }
  }
  return -1
}

function checkSanitizeDeprecation (opt) {
  if (opt && opt.sanitize && !opt.silent) {
    console.warn('index(): sanitize and sanitizer parameters are deprecated since version 0.7.0, should not be used and will be removed in the future. Read more here: https://marked.js.org/#/USING_ADVANCED.md#options')
  }
}

/**
 * Marked
 */

function index (src, opt, callback) {
  // throw error in case of non string input
  if (typeof src === 'undefined' || src === null) {
    throw new Error('index(): input parameter is undefined or null')
  }
  if (typeof src !== 'string') {
    throw new Error('index(): input parameter is of type ' +
            Object.prototype.toString.call(src) + ', string expected')
  }

  if (callback || typeof opt === 'function') {
    if (!callback) {
      callback = opt
      opt = null
    }

    opt = merge({}, index.defaults, opt || {})
    checkSanitizeDeprecation(opt)

    var highlight = opt.highlight
    var tokens
    var pending
    var i = 0

    try {
      tokens = Lexer.lex(src, opt)
    } catch (e) {
      return callback(e)
    }

    pending = tokens.length

    var done = function (err) {
      if (err) {
        opt.highlight = highlight
        return callback(err)
      }

      var out

      try {
        out = Parser.parse(tokens, opt)
      } catch (e) {
        err = e
      }

      opt.highlight = highlight

      return err
        ? callback(err)
        : callback(null, out)
    }

    if (!highlight || highlight.length < 3) {
      return done()
    }

    delete opt.highlight

    if (!pending) return done()

    for (; i < tokens.length; i++) {
      (function (token) {
        if (token.type !== 'code') {
          return --pending || done()
        }
        return highlight(token.text, token.lang, function (err, code) {
          if (err) return done(err)
          if (code == null || code === token.text) {
            return --pending || done()
          }
          token.text = code
          token.escaped = true
          --pending || done()
        })
      })(tokens[i])
    }

    return
  }
  try {
    if (opt) opt = merge({}, index.defaults, opt)
    checkSanitizeDeprecation(opt)
    return Parser.parse(Lexer.lex(src, opt), opt)
  } catch (e) {
    e.message += '\nPlease report this to https://github.com/markedjs/marked.'
    if ((opt || index.defaults).silent) {
      return '<p>An error occurred:</p><pre>' +
                escape(e.message + '', true) +
                '</pre>'
    }
    throw e
  }
}

/**
 * Options
 */

index.options =
    index.setOptions = function (opt) {
      merge(index.defaults, opt)
      return index
    }

index.getDefaults = function () {
  return {
    baseUrl: null,
    breaks: false,
    gfm: true,
    headerIds: true,
    headerPrefix: '',
    highlight: null,
    langPrefix: 'language-',
    mangle: true,
    pedantic: false,
    renderer: new Renderer(),
    sanitize: false,
    sanitizer: null,
    silent: false,
    smartLists: false,
    smartypants: false,
    xhtml: false
  }
}

index.defaults = index.getDefaults()

/**
 * Expose
 */

index.Parser = Parser
index.parser = Parser.parse

index.Renderer = Renderer
index.TextRenderer = TextRenderer

index.Lexer = Lexer
index.lexer = Lexer.lex

index.InlineLexer = InlineLexer
index.inlineLexer = InlineLexer.output

index.Slugger = Slugger

index.parse = index

export default index
